/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package com.sun.org.apache.xml.internal.security.keys.storage.implementations;

import java.security.cert.Certificate;
import java.security.cert.X509Certificate;
import java.util.Iterator;
import java.util.NoSuchElementException;

import com.sun.org.apache.xml.internal.security.keys.storage.StorageResolverSpi;

/**
 * This {@link StorageResolverSpi} makes a single {@link X509Certificate}
 * available to the {@link com.sun.org.apache.xml.internal.security.keys.storage.StorageResolver}.
 */
public class SingleCertificateResolver extends StorageResolverSpi {

  /**
   * Field certificate
   */
  private X509Certificate certificate = null;

  /**
   * @param x509cert the single {@link X509Certificate}
   */
  public SingleCertificateResolver(X509Certificate x509cert) {
    this.certificate = x509cert;
  }

  /**
   * @inheritDoc
   */
  public Iterator<Certificate> getIterator() {
    return new InternalIterator(this.certificate);
  }

  /**
   * Class InternalIterator
   */
  static class InternalIterator implements Iterator<Certificate> {

    /**
     * Field alreadyReturned
     */
    boolean alreadyReturned = false;

    /**
     * Field certificate
     */
    X509Certificate certificate = null;

    /**
     * Constructor InternalIterator
     */
    public InternalIterator(X509Certificate x509cert) {
      this.certificate = x509cert;
    }

    /**
     * @inheritDoc
     */
    public boolean hasNext() {
      return !this.alreadyReturned;
    }

    /**
     * @inheritDoc
     */
    public Certificate next() {
      if (this.alreadyReturned) {
        throw new NoSuchElementException();
      }
      this.alreadyReturned = true;
      return this.certificate;
    }

    /**
     * Method remove
     */
    public void remove() {
      throw new UnsupportedOperationException("Can't remove keys from KeyStore");
    }
  }
}
